When Gerhard Weinberg returned to Germany in 1962, he hadn't seen his hometown of Hannover for more than twenty years. The buildings on his old street, rebuilt after the relentless bombings of the war, looked brand new. He stopped across the street from his family's old apartment building. “I burst out laughing,” Weinberg remembered. He thought to himself that British bombers must have had very good aim. “The one building they didn't hit was the one we had lived in.”

That house was the site of many unhappy memories. In 1934, Weinberg's father, who had lost his government job on account of his Jewishness, started using the living room to advise desperate emigrants. A couple of years later, when Weinberg's classmates started beating up Jewish students, home became a place to avoid. “I would get terrible nosebleeds and, on the way home from school, would hide out somewhere until it stopped,” he said. “I didn't want to upset my mother.”

Weinberg, who is now eighty-seven and retired, spent his career dredging up ugly memories from the remnants of the Second World War. In 1938, as a nine-year-old, he fled Germany to escape Hitler's regime. In 1962, as a professional historian, he returned to investigate Hitler's legacy. By that time, he was not only an émigré from Nazi Germany but also Hitler's editor: Weinberg had discovered the dictator's second book, a manifesto about race and foreign policy that had been unpublished and was largely unknown. With help from Munich's Institute of Contemporary History, he made sure it didn't stay that way.

In 2016, the Institute of Contemporary History will publish Hitler again, issuing the first German edition of “Mein Kampf” since 1945—over objections that the book could offend Jewish groups or stoke the fires of neo-Nazism. In 2013, a government official from the state of Bavaria—which holds the expiring copyright—threatened to file a criminal complaint against new editions; the culture minister declared that “many conversations with Holocaust victims and their families have shown us that any sort of reprint of the disgraceful writings would cause enormous pain.” Bavaria eventually decided to let the institute proceed, but the threat of a lawsuit hangs over future editions.

The new two-thousand-page text, which surrounds Hitler’s prose with side-by-side commentary and more than three thousand footnotes, comes out in early January. Weinberg says it’s about time.

Born to middle-class Jewish parents, in 1928, the same year that Hitler wrote his second book, Weinberg said that, when he was a boy, his grandfather used to take him to a train-switching yard in Düsseldorf. The steam engines “would go puff-puff under the bridge we walked on,” he said. “We would disappear in the smoke, and then reappear.” The Nazi Party rose to power when Weinberg was five. He often went to the Hannover Zoo, which, in a country increasingly closed-off to Jews, gave him a curious connection to the wider world. He used to stare at hyperactive prairie dogs that had been brought from America. “For a very minimal fee kids up to a certain weight could get a ride on a big turtle—one of those Galápagos turtles,” he recalled, sounding incredulous at the very idea.

After Weinberg's father started working as an emigration adviser—he had been a judge, before the German legal system stopped employing Jews—visitors began streaming through the apartment as if it were a train station, inquiring about visas, taxes, and quotas. “The entrance hall of our apartment became the waiting room,” Weinberg said. Their house was a first stop in the journey out of Germany. Weinberg's parents soon considered following in the footsteps of their clients; they had a relative in the United States who was willing to sponsor the family. But strict refugee quotas slowed the process.

In 1938, Weinberg was kicked out of school, and policemen arrested his father. German banks froze Jewish accounts; Weinberg's mother had to ask her own children if they had any spare cash. On November 9th, Hannover's synagogue was burned to the ground, and local newspapers proudly printed photographs of the destruction. In German, the synagogue was called Gotteshaus, or house of God; Weinberg walked past it almost every day. “How and why people were so mad at God that they would burn down and destroy God's house—that seemed to me, at the time, in a totally different category of horror.”

Weinberg and his siblings escaped Germany through the Kindertransport. His father narrowly avoided deportation to a concentration camp, thanks to a former employer who demanded he be released. The family was reunited in England and spent 1939 waiting for American quotas to let them through. They eventually settled in Albany; after a postwar stint in the military, Weinberg studied history at the University of Chicago, focussing on the Second World War and foreign policy. In the nineteen-fifties, he led the microfilming of confiscated German documents, in Alexandria, Virginia. One day, a soldier asked him if he was from Hannover. “He showed me the November, 1938, list,” Weinberg remembered. “The arrest list with my father's name on it.”

Weinberg's workplace was itself a relic of the war. “At the edge of the Potomac River is a big building that was originally a torpedo factory,” he said. The building stored confiscated German records, “thousands and thousands of linear feet of documents.” Some were kept locked in safes, as if to suggest that documents can be just as incendiary as armaments. As Weinberg read about the early years of Nazi Germany, he began to hear about a manuscript that could change the course of his research. A former employee of the Nazi Party's publishing house recalled a book on foreign policy that Hitler had dictated but never published. Hitler himself had mentioned it, in 1942. Weinberg knew that such a book might simply be gathering dust in an archive somewhere. “It was also entirely possible that no copies survived,” he said.

One day, in the summer of 1958, Weinberg was in his office, looking through a batch of files. He opened a thick folder that was labelled as a partial draft of “Mein Kampf.” “It was mislabelled, as I discovered in the opening lines,” Weinberg said. He recognized the twisted logic of the writer but not the writing itself. “Politics is history in the making,” the first line declared. “History itself represents the progression of a people's struggle for survival.” The author argued that foreign policy helps a people preserve itself; self-preservation requires war. There were familiar accusations about Jewish conspiracies, but there were also completely new elements, like an early prediction of war with the United States.

“I was very excited,” Weinberg said. He showed a colleague, who felt the text was authentic. Around the same time, Weinberg received a message from Munich's Institute of Contemporary History, asking if he'd ever heard of a sequel to “Mein Kampf.” “I wrote them back and told them, yeah, I just found it!”

The Institute of Contemporary History published the “Zweites Buch” (“Second Book”) with Weinberg's commentary in 1961. But while he was showing the manuscript to academic publishers in the United States, an unofficial English edition appeared with a spotty translation and introduction. After that, “everyone turned me down,” he said. “They didn't want to be Hitler's publisher, and they knew there was this pirated edition.”

Here, the story of the “Second Book” closely parallels that of “Mein Kampf.” Nazi copyrights had been seized by the United States, in 1945, but they quickly reverted back to the government of Bavaria. In an echo of postwar “denazification,” “Mein Kampf” was kept strictly out of print. Florian Sepp, a historian at the Bavarian State Library, summed up the official stance, for the Washington Post: “This book is too dangerous for the general public.”

The problem with this approach, Weinberg said, was that millions of copies of “Mein Kampf” already existed in 1945—they simply lacked the context and commentary that a critical edition can provide. In his introduction to the “Second Book,” which was finally published officially in 2003, Weinberg wrote, “Germany and the rest of the world have not yet come close to coming to terms with Hitler as a person, as leader of a great nation, and as a symbol.” The publication history of his books seems to support Weinberg's point. In 1961, publishers were afraid of Hitler's second book. In 2013, the state of Bavaria showed that it was still afraid of his first. The lack of critical editions didn't prevent readers from accessing Hitler's ideas—instead, it prevented historians from shaping the way these books are remembered.

For Weinberg the practice of history is a kind of defiance against forgetting. For years, there was a pivotal event from his own life that he couldn't recall: the day in November, 1938, when his school's headmaster announced that all Jewish students were expelled. “I repressed that memory,” Weinberg said. “That was a very traumatic experience.” Then, in 2001, Weinberg visited Hannover again. This time, he met up with two of his former classmates. Now in their seventies, they talked about their shared boyhoods. Weinberg listened to them describe that strange day. After a moment, the smoke cleared, and he remembered.